.lesson {
  width: 1200px;
  margin: 0 auto;
}
.lesson-tip {
  width: 1200px;
  padding: 24px 0;
  line-height: 20px;
}
.lesson-tip span,
.lesson-tip a {
  color: #3e454d;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.3s;
}
.lesson-tip span:hover {
  color: #2080f7;
}
.lesson-play {
  width: 100%;
  height: 540px;
  font-size: 0;
}
.lesson-player {
  width: 850px;
  height: 100%;
  background-color: #3e454d;
  display: inline-block;
  vertical-align: top;
}
.lesson-play-list {
  width: 350px;
  height: 100%;
  overflow-y: auto;
  display: inline-block;
  vertical-align: top;
  background-color: #1b2128;
  transition: all 0.5s;
}
.lesson-play-list-item-wrapper {
  padding-top: 12px;
  height: 479px;
  overflow-y: auto;
}
.lesson-play-list-title {
  height: 48px;
  line-height: 48px;
  border-bottom: 1px solid #000000;
}
.lesson-play-list-title span {
  display: inline-block;
  height: 48px;
  line-height: 48px;
  font-size: 16px;
  font-weight: 400;
  padding: 0 18px;
  position: relative;
  color: #ffffff;
  cursor: pointer;
}
.lesson-play-list-title span::after {
  content: "";
  display: block;
  background-color: royalblue;
  width: 16px;
  height: 3px;
  border-radius: 1.5px;
  background-color: #2080f7;
  transition: 0.3s;
  position: absolute;
  bottom: 0;
  left: 50%;
  margin-left: -8px;
}
.lesson-play-list-item {
  margin: 0 12px;
  padding: 12px;
  cursor: pointer;
}
.lesson-play-list-item-left {
  display: inline-block;
  vertical-align: top;
  width: 14px;
  height: 14px;
  margin-top: 3px;
  margin-right: 14px;
}
.lesson-play-list-item-left img {
  width: 18px;
  height: 18px;
}
.lesson-play-list-item-right {
  display: inline-block;
  width: 263px;
  vertical-align: top;
}
.lesson-play-list-item-right-title {
  width: 263px;
  height: 20px;
  line-height: 20px;
  font-size: 14px;
  color: #a1a9b2;
  margin-bottom: 4px;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  word-wrap: normal;
}
.lesson-play-list-item-right-time {
  width: 263px;
  height: 16px;
  line-height: 16px;
  font-size: 12px;
  color: #667280;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  word-wrap: normal;
}
.lesson-play-list-item.active {
  background: #0f1419;
  border-radius: 16px;
  font-weight: 400;
}
.lesson-play-list-item.active * {
  color: #2080f7;
}

/* 自定义整个滚动条 */
::-webkit-scrollbar {
  width: 10px; /* 设置滚动条的宽度 */
}

/* 自定义滚动条轨道 */
::-webkit-scrollbar-track {
  background: #1b2128; /* 设置轨道的背景颜色 */
}

/* 自定义滚动条的滑块（thumb） */
::-webkit-scrollbar-thumb {
  background: rgb(88, 100, 112); /* 设置滑块的背景颜色 */
  border-radius: 8px;
}
.lesson-title {
  margin-top: 24px;
}
.lesson-title p {
  font-size: 24px;
  line-height: 32px;
  color: #0f1419;
  max-width: calc(1200px - 360px);
  -webkit-flex: 1 100%;
  flex: 1 100%;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  word-wrap: normal;
}
.lesson-tag {
  margin-top: 8px;
}
.lesson-tag-item {
  display: inline-block;
  border: 1px solid #edeff2;
  border-radius: 8px;
  background-color: hsla(0, 0%, 100%, 0.6);
  margin-right: 12px;
  margin-bottom: 4px;
  padding: 0 8px;
  -webkit-justify-content: center;
  justify-content: center;
  line-height: 1;
  font-size: 14px;
  color: #667280;
  height: 28px;
  line-height: 28px;
  cursor: pointer;
  transition: all 0.3s;
}
.lesson-tag-item:hover {
  color: #333;
  background-color: rgb(191, 191, 191);
}
.lesson-intro {
  background-color: rgb(245, 248, 255);
  padding: 20px 0;
}
.intro {
  width: 1200px;
  margin: 0 auto;
  font-size: 0;
}
.intro-left {
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 3px 12px rgba(0, 36, 153, 0.06);
  width: 820px;
  display: inline-block;
  vertical-align: top;
  padding-bottom: 20px;
}
.intro-left-title {
  padding-top: 10px;
}
.intro-left-title span {
  display: inline-block;
  margin: 0 20px;
  padding: 0 20px;
  font-size: 16px;
  height: 44px;
  line-height: 44px;
  color: #0f1419;
  position: relative;
  cursor: pointer;
}
.intro-left-title span.active {
  font-size: 18px;
}
.intro-left-title span.active::after {
  content: "";
  display: block;
  background-color: royalblue;
  width: 24px;
  height: 3px;
  border-radius: 1.5px;
  background-color: #2080f7;
  position: absolute;
  bottom: 0;
  left: 50%;
  margin-left: -12px;
}
.intro-right {
  padding: 24px 20px;
  margin-left: 20px;
  width: 320px;
  vertical-align: top;
  display: inline-block;
  position: relative;
  margin-bottom: 0;
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 3px 12px rgba(0, 36, 153, 0.06);
}
.intro-right .title {
  height: 24px;
  font-family: PingFang SC, sans-serif;
  font-style: normal;
  font-weight: 600;
  font-size: 18px;
  line-height: 24px;
  color: #00061a;
}
.rela-lesson {
  font-size: 0;
  margin-top: 16px;
}
.rela-lesson-imger {
  background-image: url('../img/p1.png');
  background-position: center;
  background-size: cover;
  width: 142px;
  height: 80px;
  border-radius: 6px;
  display: inline-block;
  vertical-align: top;
}
.rela-lesson-content {
  display: inline-block;
  vertical-align: top;
  margin-left: 12px;
}
.rela-lesson-content p {
  width: 166px;
  font-weight: 500;
  font-size: 14px;
  line-height: 20px;
  color: var(--color-grey-dark-2);
  white-space: normal;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  margin: unset;
  color: #667280;
  height: 40px;
}
.rela-lesson-content span {
  font-weight: 400;
  font-size: 12px;
  line-height: 16px;
  color: #667280;
  height: 16px;
  margin-top: 2px;
  display: block;
}
.rela-lesson-content em {
  display: block;
  font-style: normal;
  font-weight: 500;
  font-size: 14px;
  line-height: 20px;
  margin-top: 2px;
  height: 16px;
  color: #ff7a38;
}
.intro-left-item {
  padding: 40px 20px 0 20px;
}
.intro-left-item-title {
  color: #0f1419;
  font-size: 18px;
  font-weight: 700;
  line-height: 24px;
  margin: 0 0 16px;
}
.intro-left-item-get {
  color: #586470;
  padding: 0 0 0 16px;
  position: relative;
  font-size: 14px;
  margin-bottom: 8px;
}
.intro-left-item-get::before {
  top: 8px;
  left: 0;
  width: 6px;
  height: 6px;
  content: "";
  border-radius: 50%;
  position: absolute;
  background-color: #a1a5b2;
}
.intro-left-item-details {
  font-size: 14px;
}
.intro-left-item-details img {
  max-width: 100%;
}
.lesson-list-tab {
  display: none;
}
.lesson-list {
  margin-top: 20px;
}
.lesson-list-title {
  margin-bottom: 20px;
  padding: 16px;
  background: #f5f8fa;
  border-radius: 12px;
  margin-bottom: 16px;
  cursor: pointer;
}
.lesson-list-title span:first-child {
  font-weight: 500;
  font-size: 18px;
  height: 22px;
  line-height: 22px;
  color: #3e454d;
  margin-right: 8px;
  display: inline-block;
  vertical-align: top;
}
.lesson-list-title span:nth-child(2) {
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  word-wrap: normal;
  font-weight: 500;
  font-size: 16px;
  height: 22px;
  line-height: 22px;
  color: #3e454d;
  display: inline-block;
  vertical-align: top;
  width: 698px;
}
.lesson-list-title img {
  width: 16px;
  height: 16px;
  margin-top: 4px;
}
.lesson-list-tab {
  padding: 0 20px;
}
.lesson-list-item {
  margin: 0 12px;
  padding: 12px;
  cursor: pointer;
}
.lesson-list-item-left {
  display: inline-block;
  vertical-align: top;
  width: 14px;
  height: 14px;
  margin-top: 3px;
  margin-right: 14px;
}
.lesson-list-item-left img {
  width: 18px;
  height: 18px;
  transition: all 0.3s;
}
.lesson-list-item-right {
  display: inline-block;
  width: 700px;
  vertical-align: top;
  border-bottom: 1px solid #eeeeee;
}
.lesson-list-item-right-title {
  width: 700px;
  height: 20px;
  line-height: 20px;
  font-size: 14px;
  color: #3e454d;
  margin-bottom: 4px;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  word-wrap: normal;
}
.lesson-list-item-right-time {
  width: 700px;
  height: 16px;
  line-height: 16px;
  font-size: 12px;
  color: #667280;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  word-wrap: normal;
  margin-bottom: 20px;
}
.lesson-list-item-wrapper {
  display: none;
}
.lesson-list.active .lesson-list-item-wrapper {
  display: block;
  transition: all 0.3s;
}
.lesson-play-list-item-title {
  padding: 12px 24px;
  font-size: 16px;
  color: #a1a9b2;
  cursor: default;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  word-wrap: normal;
}
.lesson-player > img {
  display: none;
}
.lesson-play-list-title img{
  display: none;
}
@media screen and (max-width: 768px) {
  .lesson {
    width: 100%;
  }
  .lesson-tip {
    width: 95%;
    margin: 0 auto;
  }
  .lesson-play-list {
    display: none;
  }
  .lesson-play {
    width: 95%;
    margin: 0 auto;
  }
  .lesson-player {
    width: 100%;
  }
  .intro {
    width: 95%;
    margin: 0 auto;
  }
  .intro-left,
  .intro-right {
    display: block;
    width: 100%;
  }
  .intro-right {
    width: calc(100% - 40px);
    margin-left: 0;
    margin-top: 20px;
  }
  .lesson-title,
  .lesson-tag {
    width: 95%;
    margin: 10px auto;
  }
  .lesson-list-title {
    display: flex;
  }
  .lesson-list-title span:first-child {
    flex: 0 0 30px;
  }
  .lesson-list-title span:nth-child(2) {
    flex: 1;
  }
  .lesson-list-title img {
    flex: 0 0 18px;
  }
  .lesson-list-item {
    display: flex;
  }
  .lesson-list-item-left {
    flex: 0 0 20px;
  }
  .lesson-list-item-right {
    flex: 1;
  }
  .intro-left-title {
    text-align: center;
  }
  .lesson-player {
    position: relative;
  }
  .lesson-player > img {
    position: absolute;
    top: 10px;
    right: 10px;
    width: 20px;
    height: 20px;
    display: block;
  }
  .lesson-play{
    position: relative;
  }
  .lesson-play-list-title{
    display: flex;
    justify-content: space-between;
  }
  .lesson-play-list-title img{
    display: block;
    width: 20px;
    margin-right: 20px;
    padding-top: 15px;
    height: 20px;

  }
}
